Oxygen Scross MTB ongoing review

[Deleted member 4366]

Try taking the battery off, short the connector on the bike to discharge the capacitor in the controller, then re-connect and try again. Repeat a few times if it doesn't work first time. The controller must have a self-learning routine that has re-learnt incorrectly.

There's nothing you can do in the motor assembly or connection that can make the motor go backwards.

 

[Andy Bluenoes]

Try taking the battery off, short the connector on the bike to discharge the capacitor in the controller, then re-connect and try again. Repeat a few times if it doesn't work first time. The controller must have a self-learning routine that has re-learnt incorrectly.

There's nothing you can do in the motor assembly or connection that can make the motor go backwards.

Thanks D8veh

Tried that a few times this morning before I had to set off to work in the car.
Massive flash when I shorted it first time, reconnected battery, still going backwards.

Not such a big spark the next few times I tried it, but all without success. Probably tried a dozen times in the end.
I shorted the battery connector once more before I left for work, and have left the battery off, see if that makes any difference when I get home later on.

Was such a nice morning to ride into work today too

 

[JPGiant]

If it was my bike, I'd strip it down again to see if a wire is trapped/nicked.
How did you manage to remove the damaged screw and was it replaced with one of exact size?

 

[Andy Bluenoes]

Yes, I did that last night after I found the initial problem.
I did think about that screw somehow causing the issue...

I had to drill it out, but only drilled the head off, and had to lever the plate a bit to get it off. I put a piece of wood under it when i levered it, to avoid any damage. Pretty sure that didn't cause any damage...there's no wiring directly under where that screw goes in, just steel.

I found a screw almost exactly the same size, very slightly fatter, but the same length to replace the knackered one.

Been googling like mad this morning, its baffling the hell out of me

 

[Deleted member 4366]

Are you sure it's going backwards and it's not just the clutch not engaging?

 

[Andy Bluenoes]

Im not sure how I would know that Dave.....I know it will spin up to maximum speed going backwards on the throttle...so do my shins as they took a good whack off the pedals going round backwards!

I also tried pedalling briefly....I could feel resistance as the motor appeared to be trying to spin the opposite way

When I took it apart the second time, I pilled the whole motor out of the outer shell as the wheel nut was off on the brake disc side....I didnt intend to do that, but as it came out, I thought id have a look inside...

The plastic wheels all looked fine, no missing or worn teeth or anything like that, and when I pushed the motor back in, it appeared to slot back in nicely

 

[Woosh]

I must say I am puzzled.
If the motor spins backward, then it should not engage the clutch.

 

[Andy Bluenoes]

How would I know if the clutch isnt working?
I just remember seeing 3 outer wheels and the cog on the motor slotted in between them...like this one

https://www.electricbike.com/three-250-watt-hub-motors/

 

[Woosh]

How would I know if the clutch isnt working?

you spin the wheel backward, it will engage the clutch and you can feel the rotor moving.

 

[Andy Bluenoes]

you spin the wheel backward, it will engage the clutch and you can feel the rotor moving.

Okay thanks...so that means then that because the wheel is spinning full speed backwards, the clutch mechanism is working ok?

 

[Woosh]

did you try to spin the wheel backward by hand? you should feel the motor resist.

 

[Andy Bluenoes]

did you try to spin the wheel backward by hand? you should feel the motor resist.

Yes....I cant remember now, but it think that when I did that with assist level on 1, the motor kicked in and started spinning the wheel backwards.

Im getting really confused by this clutch...is it inside the motor, or is it the same part that I have been referring to as the hub, which is the bit that has been replaced?

 

[Woosh]

you have to switch off the motor to test the clutch. Sign of a good clutch: spin forward: no resistance, spin backward: clutch is engaged immediately.

is it inside the motor,

yes, it's on the opposite side of the cassette mechanism. You did not touch it when re-assembling your motor, that is why I am puzzled.

 

[Deleted member 4366]

As Woosh said, the clutch won't engage if the motor spins backwards, so all you get is a whirring sound. Something doesn't add up. Did you actually see the wheel turning backwards? Firstly, it's almost impossible to get the motor to turn backwards, and secondly, if it did, the wheel wouldn't turn.

Is it just your free-hub that's jammed? That happens if you do the ring nuts too tight. Like a wheel bearing, they have to be locked together without tension on the bearing, not done up tight, like a normal nut.

 

[Andy Bluenoes]

you have to switch off the motor to test the clutch. Sign of a good clutch: spin forward: no resistance, spin backward: clutch is engaged immediately.


yes, it's on the opposite side of the cassette mechanism. You did not touch it when re-assembling your motor, that is why I am puzzled.

Thanks Tony, that makes sense. I will double check that tonight.

I did fully remove the right hand side from the left...I cant imagine there is any way that it can go back in incorrectly reversing the direction of the wheel rotation.

 

[Andy Bluenoes]

As Woosh said, the clutch won't engage if the motor spins backwards, so all you get is a whirring sound. Something doesn't add up. Did you actually see the wheel turning backwards? Firstly, it's almost impossible to get the motor to turn backwards, and secondly, if it did, the wheel wouldn't turn.

Is it just your free-hub that's jammed? That happens if you do the ring nuts too tight. Like a wheel bearing, they have to be locked together without tension on the bearing, not done up tight, like a normal nut.

The wheel definitely turns backwards on the throttle, and pedalling..although I didnt test that much as its not comfortable to do...

I can spin the freehub anticlockwise freely by hand, turning it forward, the wheel starts to rotate forwards as the locking mechanism kicks in. I didnt put much tightness on the axle nut as its quite a tight fit for the spanner I used, and remembered it wasnt on very tight in the first place.

 

[Deleted member 4366]

The free-hub can be free when the wheel is off, but it will lock when you tighten the axle nut if you have the ring-nuts wrongly adjusted.

There's no way you can assemble anything wrong to get the wheel to turn backwards.

 

[Andy Bluenoes]

Well, if you cant think of anything Dave, then its pretty much going to end up one of those unsolved mysteries.
Not much point taking it to a bike shop as most of them will run a mile when it comes to electrics.

 

[Deleted member 4366]

Check it again when you get home. What you've described is not possible.

 

[Andy Bluenoes]

Just got home Dave

Still the same.

Just put a video on YouTube

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